Camels first evolved in North America around 45 million years ago. They were only found on our continent between 3 and 5 million years ago. When they migrated to Asia and South America.
At least 9 species of camel are known from Arizona in prehistoric times. These included possible ancestors of both the Asian camels and the South American llamas.
Two species of camel are known from the Big Sandy Formation (5.1-5.6 mya) in Mohave County, Megatylopus matthewi (about 14 ft tall), and Pleiolama vera, a llama relative. Our tooth is more likely to be from a Megatylopus.
Two camels are also known from Camel Canyon’s Quiburis Formation, near Mammoth in SE Pinal County. This 5.6 million-year-old location has “Hemiauchenia” sp. (probably actually in the genus Pleiolama), and specimens of an undetermined Megatylopus species.
In more modern times Dromedary camels were imported to the U.S. in 1856, for an experiment in desert transportation by the U.S. Army. The camel train made one trip to California, but the experiment failed. After the experiment failed, one of the Army camel drivers, known as Hi Jolly (originally Philip Tedro), moved to Gila Bend, Arizona. After his own camel train business failed, he released his camels in the Gila Bend area. It’s unsure how long they lasted, but there were unconfirmed sightings into the 1970s.